CLONING AND CHARACTERIZATION OF CDNAS CODING FOR HEAVY AND LIGHT-CHAINS OF A MONOCLONAL-ANTIBODY (MABB9) SPECIFIC FOR HUMAN PLASMA APOLIPOPROTEIN B-100

Low-density lipoproteins (LDL) and LDL-cholesterol in human plasma are clinically evaluated as important markers, whose concentrations have positive correlations with the incidence of coronary artery diseases. Here, the heavy and light chain cDNAs for the Fab region of a murine m onoclonal antibody MabB9 (gamma 2b, kappa), which is specific for apol ipoprotein B-100 of human plasma LDL, were cloned and their nucleotide sequences were characterized. The sequence analyses revealed that the variable region of the heavy chain is a member of mouse heavy chain s ubgroup II(B) and that of the light chain is a member of kappa subgrou p V. Complementarity-determining regions (CDRs) 1, 2, and 3 in the var iable regions of both chains were identified. Some unusual framework r esidues in the heavy chain were also identified. The sequence analyses suggest that the cDNAs are functional.